#include <crt_str.h>
#include <crt_memory.h>


char* s_strcpy(
	char * dst,
	size_t size,
	char const* src
)
{
	rc_assert(dst != NULL, NULL)
	rc_assert(src != NULL, NULL)
	rc_assert(size > 1, NULL)

	char* p1 = dst;
	char const* p2 = src;

	size_t available = size - 1;
	while ((*p1++ = *p2++) && --available > 0)
	{
		
	}

	return dst;
}


char* s_strncpy(
	char * dest,
	const char * source,
	size_t count
)
{
	char *start = dest;

	while (count && (*dest++ = *source++))    /* copy string */
		count--;

	if (count)                              /* pad out with zeroes */
		while (--count)
			*dest++ = '\0';

	return(start);
}

char* s_strcat(
	char * dst,
	size_t size,
	const char * src
)
{
	s_strcpy (dst + strlen (dst), size, src);
	return(dst);                  /* return dst */

}


size_t s_strlcatf(char *dest, 
	size_t size, 
	const char *fmt, ...)
{
	size_t len = s_strlen(dest);
	va_list vl;

	va_start(vl, fmt);
	len += vsnprintf(dest + len, size > len ? size - len : 0, fmt, vl);
	va_end(vl);

	return len;
}


char* s_strncat(
	char * front,
	const char * back,
	size_t count
)
{
	char *s = front;

	/* Find the end of S1.  */
	front += strlen (front);

	size_t ss = s_strnlen (back, count);

	front[ss] = '\0';
	s_memcpy (front, back, ss);
    return s;

}

int s_strcmp(
	const char * src,
	const char * dst
)
{
	int ret = 0;

	while (!(ret = *(unsigned char *)src - *(unsigned char *)dst) && *dst)
        (void)(++src), ++dst;

	if (ret < 0)
		ret = -1;
	else if (ret > 0)
		ret = 1;

	return(ret);
}

int s_stricmp(
	const char * dst,
	const char * src
)
{
	const char* s1 = dst;
	const char* s2 = src;

	int f = 0;
	int l = 0;
	do
	{
		if (((f = (unsigned char)(*(s1++))) >= 'A') && (f <= 'Z'))
			f -= 'A' - 'a';
		if (((l = (unsigned char)(*(s2++))) >= 'A') && (l <= 'Z'))
			l -= 'A' - 'a';
	} while (f && (f == l));

	return(f - l);
}

int s_strcasecmp(
	const char * dst,
	const char * src
)
{
	const char* s1 = dst;
	const char* s2 = src;

	int f = 0;
	int l = 0;
	do
	{
		if (((f = (unsigned char)(*(s1++))) >= 'A') && (f <= 'Z'))
			f -= 'A' - 'a';
		if (((l = (unsigned char)(*(s2++))) >= 'A') && (l <= 'Z'))
			l -= 'A' - 'a';
	} while (f && (f == l));

	return(f - l);

}


int s_strncmp(
	const char *first,
	const char *last,
	size_t      count
)
{
	size_t x = 0;

	if (!count)
	{
		return 0;
	}

	/*
	 * This explicit guard needed to deal correctly with boundary
	 * cases: strings shorter than 4 bytes and strings longer than
	 * UINT_MAX-4 bytes .
	 */
	if (count >= 4)
	{
		/* unroll by four */
		for (; x < count - 4; x += 4)
		{
			first += 4;
			last += 4;

			if (*(first - 4) == 0 || *(first - 4) != *(last - 4))
			{
				return(*(unsigned char *)(first - 4) - *(unsigned char *)(last - 4));
			}

			if (*(first - 3) == 0 || *(first - 3) != *(last - 3))
			{
				return(*(unsigned char *)(first - 3) - *(unsigned char *)(last - 3));
			}

			if (*(first - 2) == 0 || *(first - 2) != *(last - 2))
			{
				return(*(unsigned char *)(first - 2) - *(unsigned char *)(last - 2));
			}

			if (*(first - 1) == 0 || *(first - 1) != *(last - 1))
			{
				return(*(unsigned char *)(first - 1) - *(unsigned char *)(last - 1));
			}
		}
	}

	/* residual loop */
	for (; x < count; x++)
	{
		if (*first == 0 || *first != *last)
		{
			return(*(unsigned char *)first - *(unsigned char *)last);
		}
		first += 1;
		last += 1;
	}

	return 0;
}

char* s_strchr(
	const char *string,
	int ch
)
{
	while (*string && *string != (char)ch)
		string++;

	if (*string == (char)ch)
		return((char *)string);
	return(NULL);
}
char* s_strrchr(
	const char * string,
	int ch
)
{
	char *start = (char *)string;

	while (*string++)                       /* find end of string */
		;
	/* search towards front */
	while (--string != start && *string != (char)ch)
		;

	if (*string == (char)ch)                /* char found ? */
		return((char *)string);

	return(NULL);
}


size_t s_strspn(
	const char * string,
	const char * control
)
{
	const unsigned char *str = (unsigned char const*)string;
	const unsigned char *ctrl = (unsigned char const*)control;

	unsigned char map[32];
	int count;

	/* Clear out bit map */
	for (count = 0; count < 32; count++)
		map[count] = 0;

	/* Set bits in control map */
	while (*ctrl)
	{
		map[*ctrl >> 3] |= (1 << (*ctrl & 7));
		ctrl++;
	}


	/* 1st char NOT in control map stops search */
	if (*str)
	{
		count = 0;
		while (map[*str >> 3] & (1 << (*str & 7)))
		{
			count++;
			str++;
		}
		return(count);
	}
	return(0);
}

size_t s_strcspn(
	const char * string,
	const char * control
)
{
	const unsigned char *str = (unsigned char *)string;
	const unsigned char *ctrl = (unsigned char *)control;

	unsigned char map[32];
	int count;

	/* Clear out bit map */
	for (count = 0; count < 32; count++)
		map[count] = 0;

	/* Set bits in control map */
	while (*ctrl)
	{
		map[*ctrl >> 3] |= (1 << (*ctrl & 7));
		ctrl++;
	}
	/* 1st char in control map stops search */
	count = 0;
	map[0] |= 1;    /* null chars not considered */
	while (!(map[*str >> 3] & (1 << (*str & 7))))
	{
		count++;
		str++;
	}
	return(count);
}

char* s_strpbrk(
	const char * string,
	const char * control
)
{
	const unsigned char *str = (unsigned char const*)string;
	const unsigned char *ctrl =(unsigned char const*)control;

	unsigned char map[32];
	int count;

	/* Clear out bit map */
	for (count = 0; count < 32; count++)
		map[count] = 0;

	/* Set bits in control map */
	while (*ctrl)
	{
		map[*ctrl >> 3] |= (1 << (*ctrl & 7));
		ctrl++;
	}

	/* 1st char in control map stops search */
	while (*str)
	{
		if (map[*str >> 3] & (1 << (*str & 7)))
			return((char *)str);
		str++;
	}
	return(NULL);
}


char* s_strstr(
	const char * str1,
	const char * str2
)
{
	char *cp = (char *)str1;
	char *s1, *s2;

	if (!*str2)
		return((char *)str1);

	while (*cp)
	{
		s1 = cp;
		s2 = (char *)str2;

		while (*s1 && *s2 && !(*s1 - *s2))
            (void)(s1++), s2++;

		if (!*s2)
			return(cp);

		cp++;
	}

	return(NULL);

}

size_t s_strlen(
	const char * str
)
{
	const char *char_ptr;
	const unsigned long int *longword_ptr;
	unsigned long int longword, himagic, lomagic;

	/* Handle the first few characters by reading one character at a time.
       Do this until CHAR_PTR is aligned on a longword boundary.  */
	for (char_ptr = str; ((unsigned long int) char_ptr
						  & (sizeof (longword) - 1)) != 0;
		 ++char_ptr)
		if (*char_ptr == '\0')
			return char_ptr - str;

	/* All these elucidatory comments refer to 4-byte longwords,
       but the theory applies equally well to 8-byte longwords.  */

	longword_ptr = (unsigned long int *) char_ptr;

	/* Bits 31, 24, 16, and 8 of this number are zero.  Call these bits
       the "holes."  Note that there is a hole just to the left of
       each byte, with an extra at the end:

       bits:  01111110 11111110 11111110 11111111
       bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD

       The 1-bits make sure that carries propagate to the next 0-bit.
       The 0-bits provide holes for carries to fall into.  */
	himagic = 0x80808080L;
	lomagic = 0x01010101L;
	if (sizeof (longword) > 4)
	{
		/* 64-bit version of the magic.  */
		/* Do the shift in two steps to avoid a warning if long has 32 bits.  */
		himagic = ((himagic << 16) << 16) | himagic;
		lomagic = ((lomagic << 16) << 16) | lomagic;
	}
	if (sizeof (longword) > 8)
		abort ();

	/* Instead of the traditional loop which tests each character,
       we will test a longword at a time.  The tricky part is testing
       if *any of the four* bytes in the longword in question are zero.  */
	for (;;)
	{
		longword = *longword_ptr++;

		if (((longword - lomagic) & ~longword & himagic) != 0)
		{
			/* Which of the bytes was the zero?  If none of them were, it was
               a misfire; continue the search.  */

			const char *cp = (const char *) (longword_ptr - 1);

			if (cp[0] == 0)
				return cp - str;
			if (cp[1] == 0)
				return cp - str + 1;
			if (cp[2] == 0)
				return cp - str + 2;
			if (cp[3] == 0)
				return cp - str + 3;
			if (sizeof (longword) > 4)
			{
				if (cp[4] == 0)
					return cp - str + 4;
				if (cp[5] == 0)
					return cp - str + 5;
				if (cp[6] == 0)
					return cp - str + 6;
				if (cp[7] == 0)
					return cp - str + 7;
			}
		}
	}
}
size_t	s_strnlen(
		const char * str,
		size_t maxlen
)
{
	const char *char_ptr, *end_ptr = str + maxlen;
	const unsigned long int *longword_ptr;
	unsigned long int longword, himagic, lomagic;

	if (maxlen == 0)
		return 0;

	if ((end_ptr < str))
		end_ptr = (const char *) ~0UL;

	/* Handle the first few characters by reading one character at a time.
       Do this until CHAR_PTR is aligned on a longword boundary.  */
	for (char_ptr = str; ((unsigned long int) char_ptr
						  & (sizeof (longword) - 1)) != 0;
		 ++char_ptr)
		if (*char_ptr == '\0')
		{
			if (char_ptr > end_ptr)
				char_ptr = end_ptr;
			return char_ptr - str;
		}

	/* All these elucidatory comments refer to 4-byte longwords,
       but the theory applies equally well to 8-byte longwords.  */

	longword_ptr = (unsigned long int *) char_ptr;

	/* Bits 31, 24, 16, and 8 of this number are zero.  Call these bits
       the "holes."  Note that there is a hole just to the left of
       each byte, with an extra at the end:

       bits:  01111110 11111110 11111110 11111111
       bytes: AAAAAAAA BBBBBBBB CCCCCCCC DDDDDDDD

       The 1-bits make sure that carries propagate to the next 0-bit.
       The 0-bits provide holes for carries to fall into.  */
	himagic = 0x80808080L;
	lomagic = 0x01010101L;
	if (sizeof (longword) > 4)
	{
		/* 64-bit version of the magic.  */
		/* Do the shift in two steps to avoid a warning if long has 32 bits.  */
		himagic = ((himagic << 16) << 16) | himagic;
		lomagic = ((lomagic << 16) << 16) | lomagic;
	}
	if (sizeof (longword) > 8)
		abort ();

	/* Instead of the traditional loop which tests each character,
       we will test a longword at a time.  The tricky part is testing
       if *any of the four* bytes in the longword in question are zero.  */
	while (longword_ptr < (unsigned long int *) end_ptr)
	{
		/* We tentatively exit the loop if adding MAGIC_BITS to
       LONGWORD fails to change any of the hole bits of LONGWORD.

       1) Is this safe?  Will it catch all the zero bytes?
       Suppose there is a byte with all zeros.  Any carry bits
       propagating from its left will fall into the hole at its
       least significant bit and stop.  Since there will be no
       carry from its most significant bit, the LSB of the
       byte to the left will be unchanged, and the zero will be
       detected.

       2) Is this worthwhile?  Will it ignore everything except
       zero bytes?  Suppose every byte of LONGWORD has a bit set
       somewhere.  There will be a carry into bit 8.  If bit 8
       is set, this will carry into bit 16.  If bit 8 is clear,
       one of bits 9-15 must be set, so there will be a carry
       into bit 16.  Similarly, there will be a carry into bit
       24.  If one of bits 24-30 is set, there will be a carry
       into bit 31, so all of the hole bits will be changed.

       The one misfire occurs when bits 24-30 are clear and bit
       31 is set; in this case, the hole at bit 31 is not
       changed.  If we had access to the processor carry flag,
       we could close this loophole by putting the fourth hole
       at bit 32!

       So it ignores everything except 128's, when they're aligned
       properly.  */

		longword = *longword_ptr++;

		if ((longword - lomagic) & himagic)
		{
			/* Which of the bytes was the zero?  If none of them were, it was
               a misfire; continue the search.  */

			const char *cp = (const char *) (longword_ptr - 1);

			char_ptr = cp;
			if (cp[0] == 0)
				break;
			char_ptr = cp + 1;
			if (cp[1] == 0)
				break;
			char_ptr = cp + 2;
			if (cp[2] == 0)
				break;
			char_ptr = cp + 3;
			if (cp[3] == 0)
				break;
			if (sizeof (longword) > 4)
			{
				char_ptr = cp + 4;
				if (cp[4] == 0)
					break;
				char_ptr = cp + 5;
				if (cp[5] == 0)
					break;
				char_ptr = cp + 6;
				if (cp[6] == 0)
					break;
				char_ptr = cp + 7;
				if (cp[7] == 0)
					break;
			}
		}
		char_ptr = end_ptr;
	}

	if (char_ptr > end_ptr)
		char_ptr = end_ptr;
	return char_ptr - str;
}

char* s_strtok(
	char*       str,
	char const* delim,
	char**      context
)
{
	char *end;
	if (str == NULL)
		str = *context;
	if (*str == '\0')
	{
		*context = str;
		return NULL;
	}
	/* Scan leading delimiters.  */
	str += s_strspn(str, delim);
	if (*str == '\0')
	{
		*context = str;
		return NULL;
	}
	/* Find the end of the token.  */
	end = str + s_strcspn(str, delim);
	if (*end == '\0')
	{
		*context = end;
		return str;
	}
	/* Terminate the token and make *SAVE_PTR point past it.  */
	*end = '\0';
	*context = end + 1;
	return str;
}


char*  s_strset(
	char * string,
	int val
)
{
	char *start = string;

	while (*string)
		*string++ = (char)val;

	return(start);
}

char*  s_strrev(
	char * string
)
{
	char *start = string;
	char *left = string;
	char ch;

	while (*string++)                 /* find end of string */
		;
	string -= 2;

	while (left < string)
	{
		ch = *left;
		*left++ = *string;
		*string-- = ch;
	}

	return(start);
}



